Depending upon the quantity of protein being consumed, one or more unit doses of a blend of L-Tryptophan (80 mgs), L-Methionine (90 mgs), L-Valine (103 mgs) and L-Lysine monohydrochloride (128 mgs) was calculated to be a universal dietary supplement for 61 commonly used foods (C. I. Jarowski, U.S. Pat. No. 5,559,142). The levels of supplementation were derived by taking into account the average human fasting plasma concentrations of the eight essential amino acids plus L-Tyrosine and L-Cystine. The latter two non-essential amino acids were included since they are L-Phenylalanine-sparing and L-Methionine-sparing respectively.
Earlier studies in Sprague-Dawley rats demonstrated that essential amino acid supplemented rations lowered serum urea levels 44% (G. M. Torre, V. D. Lynch and C. I. Jarowski, J. Pharm. Sci., 70, 114 (1981). The levels of L-Tryptophan, L-Lysine and L-Threonine used to supplement the commercial rat ration were derived by taking into account the average fasting plasma concentrations of the essential amino acids of Sprague-Dawley rats.
A replicated human study demonstrated that when two unit doses of the quartette of essential amino acids mentioned above were taken immediately after each meal 24-hour urinary urea was reduced 25 to 28%. The unit doses were administered in #0 hard gelatin capsules. Typical meals used are shown in Table I.